


now show me your fangs

by cosmicwoosan



Series: teeth [2]
Category: ATEEZ (Band)
Genre: Aftercare, Alternate Universe - Succubi & Incubi, Belly Bulging, Body Horror, Come Inflation, Demon Sex, M/M, Smut, Sounding, Tentacle Bondage?, Tentacle Sex, Tentacles, Throat Bulging, some hentai shit, this is just utter filth
Language: English
Status: Completed
Published: 2020-10-31
Updated: 2020-10-31
Packaged: 2021-03-08 23:41:04
Rating: Explicit
Warnings: Creator Chose Not To Use Archive Warnings
Chapters: 1
Words: 3,743
Publisher: archiveofourown.org
Story URL: https://archiveofourown.org/works/27295081
Author URL: https://archiveofourown.org/users/cosmicwoosan/pseuds/cosmicwoosan
Summary: San has learned a thing or two since they'd last met. Specifically, how to wield tentacles.Except Seonghwa is a millennium older. It's only natural he'd have them too.
Relationships: Choi San/Park Seonghwa
Series: teeth [2]
Series URL: https://archiveofourown.org/series/1992883
Comments: 8
Kudos: 171





	now show me your fangs

**Author's Note:**

> demon sanhwa's at it again!! kinda went all out on this one... happy spooky day :)
> 
> there is some graphic/disturbing body imagery in this one so if you're made squeamish by anything in the tags i suggest u don't read
> 
> this can be read as a standalone piece but i highly suggest reading the first part! as a quick rundown, seonghwa is an ancient, over a thousand years old, and san is a newblood, a couple hundred years old.

Humans are real fucking stupid sometimes. Summoning demons on purpose just to see if it’s real? What the hell else do they expect when they draw a demonic symbol on their floor, chant something in a foreign, probably dead language, and sometimes sacrifice a living animal? Of fucking _course_ something evil is going to appear.

And it’s not like San _wants_ to adhere to stupid summoning rituals. Unfortunately, for a demon of his standing, he doesn’t have the power to withstand rituals just yet. Which is fucking ridiculous in his opinion; he’s going on two hundred years old and he can’t stop himself from getting dragged onto the Earth plane because of some ritual? Fucking pathetic.

He’s dragged into some human’s musty apartment, candlelit and run down. At first glance, it doesn’t even look like an apartment, but then he sees a feeble-looking man sitting cross-legged on the floor, eyes screwed shut, clutching something in his hands.

“What?” San says through clenched teeth.

The human’s eyes pop open, mouth dropping as he opens up his hands to reveal a chain necklace with a cross for a pendant. San cocks an eyebrow at him. “You’re joking, right? You summoned a demon, only to have something to ward it off? News flash, buddy, those little crosses don’t work on incubi.”

The human’s mouth opens and closes as he splutters for words, the cross falling from his palms and clattering onto the floor. “W-wait, what are you going to do?” the human shouts, already beginning to scramble backwards even though San hasn’t moved an inch.

“Sheesh, what was the purpose of summoning a demon if you’re just gonna run away from it? You humans have some fucking nerve, just summoning us for the hell of it.” San steps out of the symbol painted on the wooden floors, towards the human, who’s backed himself up against a wall. He kneels down, leveling himself with the mortal. “What’s your name, sweetheart?”

“S-sweetheart?” the human croaks, breath tickling San’s face.

As annoyed as he gets with humans, they _are_ his food source. And this one’s pretty cute, all big eyes and perfectly sculpted jaw and crooked teeth. Give him some red eyes and he himself could be an incubus.

“You heard me. Sweetheart. Or… you like to go by baby boy, don’t you?”

The stranger’s eyes widen even further. “H-how the fuck do you know that?” he screams.

“You summoned an _incubus_ , baby boy,” San teases, smirking, a clawed finger grazing the human’s jaw. “Do you know what that is and what it means for you?”

The poor boy’s heart thuds heavily in his chest as his Adam’s apple bobs in his throat, eyes falling to the side as if to search for some conveniently placed weapon, but alas, he is alone in the room with nobody but a sex demon. “Y-you… what are you going to do to me?”

“Mm, see, I _could_ kill you if I really wanted to.” San leans in, inhaling the human’s vanilla scent, reeking of innocence.

A virgin.

“P-please don’t,” the human pleads shakily. He’s visibly trembling, and San can hear every bead of sweat that seeps out from his pores.

“I’m not going to kill you, baby boy,” San teases, bringing up more of his fingers to cup the human’s jaw. He tenses, flinching at San’s touch. “You’re cute. And you smell…” He inhales deeply. “...divine.”

The human winces, recoiling back against the wall as San drags his claws down his jaw, his neck, coming to a stop at the collar of his t-shirt. “So why _did_ you summon me? You know what an incubus is, right?” The human gulps and nods. “Did you summon a sex demon on purpose?”

“I-I…”

“Do you want me to rid you of your innocence?” San asks, his grin growing. “I’ll have you know, virgins are the _best_ food for me.”

“F-food?”

San’s mouth expands into a full-fanged smile, his eyes ablaze as he hooked one of his claws underneath the collar of the human’s shirt.

“Mhm, a full three-course meal.”

As San leans in, however, there is a force yanking him backwards, as if someone else were pulling him by his shirt. As if he’s entering the rifts between dimensions, on an involuntary trip back to his space… except it’s not _his_ space. The momentum knocks everything in his body around, head spinning by the time he comes to a full stop, his feet above nothing but space.

When he finally manages to open his eyes again, there are two glaring purple irises staring back at him.

“What the fuck? Who—”

San’s mouth drops open as soon as he realizes.

“Long time no see,” the ancient says, followed by a chuckle. Donned in all black, arms crossed, stance poised, Seonghwa stands as the king of his space—black and blue and purple waves undulating around them, the groans of his underlings resonating below.

There’s no way San could forget this place. He doesn’t remember how long it’s been, but how could he forget?

“What the fuck do you want?” San snarls, fangs bared.

“What do you think, newblood?” A corner of Seonghwa’s mouth curves up into a devilish smirk. “Remember when we parted ways? The pact we made?”

“Pacts between demons don’t exist, asshole. That shit was unofficial.” San’s talons emerge upon instinct, though there isn’t much he can do with them in a situation like this. Seonghwa has his own, and certainly his shadow hands do too. “Congratulations, you have the power to yank me out of dimensions. Now if you’ll excuse me—”

Seonghwa lets out a low, dark chuckle. “I don’t think so, newblood.” The sea of hands rise from below, their sinister claws itching for a taste of San’s skin, but even San can tell Seonghwa is restraining them. Seonghwa is _toying_ with him. “My darlings and I want to have a little fun, and you’re the perfect candidate. They absolutely adored you last time.”

San scoffs, his eyes ablaze.

“Hey, Seonghwa.”

“Hm?”

“How long has it been since we last saw each other?”

Seonghwa pauses. “Hm… I’m not quite sure, if I’m being honest.”

San smirks, his claws extending further. “Well, I’ll have you know that you’re not the only one with tricks up his sleeves now.”

Seonghwa cocks an eyebrow at him, and San has the pleasure of watching the ancient’s face fall as soon as his tendrils burst out from behind him, coiling around Seonghwa’s legs and arms, the black ooze singeing his clothes away.

“Oh, you can summon underlings now?” Seonghwa taunts from above, his face broken out into a wide, careless grin. He laughs, _laughs_ , a haughty noise that distorts off the colors around them. The hands seem to wave at the sound. “Cute, newblood, very c—”

“I’m not a child!” San bellows, voice ripping through the space as one of the tendrils shoves its way into Seonghwa’s mouth, silencing him. Seonghwa makes a garbled sound at the abrupt intrusion but nothing more. “Yeah, I have underlings now. I’ve grown much more powerful since we’ve last met.”

Though Seonghwa is rendered speechless, his voice rings in San’s head.

_“Then prove it.”_

Seonghwa’s own claws emerge from the tips of his fingers as the wall splits behind him, much like it did for San, only to reveal a mass of wriggling purple tentacles, squirming past the split and into the space.

“Shit,” San mutters to himself.

_“I have lived for over a thousand years, newblood.”_

An angry fire burns in the pit of San’s stomach, his eyes stinging with fury. He _knows_ Seonghwa is older and therefore more powerful, so he lets it happen; he lets the purple things wrap around his body and tear off his clothes, he lets the hands from below hoist him up until he’s level with their master, eye to eye, red on purple. Even with his mouth impaled by a tentacle, San can tell Seonghwa is smiling.

_“I commend you, newblood. The taste is… addicting.”_

San scowls, forcing the tendril further down his throat, until he can see the rounded shape bulging from the ancient’s throat. Seonghwa lets out a subdued groan as black ooze gushes from his mouth with each thrust, landing in droplets on his shoulders and trails from the corners of his mouth. A cluster of them slink across Seonghwa’s porcelain skin, spreading his legs open until San can see every muscle, every nuance of his body.

Two of Seonghwa’s tentacles bind San’s hands above his head, but it’s to be expected. He’s _expecting_ this. He’s outnumbered, clearly, and the only advantage he has at the moment is his single tentacle fucking Seonghwa’s mouth.

Even so, Seonghwa’s underlings are moving a little too slowly. Slow to the point where it’s suspicious.

“Well, Seonghwa?” San tests as more of Seonghwa’s tentacles snake around his body. One hovers just in front of his face as if it’s just _watching_. “Why haven’t you attacked me yet? Aren’t you going to show me what all your fancy underlings can do?”

As more black goo dribbles out of Seonghwa’s mouth, San realizes why.

“Am I… am I actually doing something to you?”

Seonghwa’s glassy purple eyes narrow in his direction, lids hooded, appearing _weak._

“Holy shit, no way,” San says in disbelief, laughing to himself. Seonghwa, big ancient incubus with _two_ sets of underlings, under _his_ influence.

_“It’s only because you got… the first move…”_

San chuckles, his tentacles bringing Seonghwa closer to him. “Come on, Seonghwa. You’re just playing with me right now. You’re gonna bring out the big guns soon, gonna start fucking me out of nowhere. So how about a compromise, hm? One that’ll benefit us both.” He glances down; his cock is standing straight against his stomach, one of Seonghwa’s tentacles lingering just below his hole. He’s waiting for it to impale him, to dig deep and wriggle around and coax however many orgasms out of him, but it stays waiting, lingering. And oddly enough, San is starting to grow impatient. “Make me cum, o powerful ancient, and I’ll do the same for you.”

A bold statement if San’s ever heard one. He knows it will be all too easy for Seonghwa to get him to cum, if he doesn’t seal him again. Seonghwa’s eyes remain lidded, but finally, the bulbous head of Seonghwa’s tentacle prods his entrance, its slipperiness making it easy to press inside. San exhales, feeling some kind of _relief_ as it nestles inside him, pushing in until it can no longer, until its outline presents itself as it bulges from San’s pelvis. His mouth drops open, the stabbing pressure from a single tentacle making every single muscle in his body spasm. And of course, that’s when Seonghwa takes the reins once again, as another purple tendril slips inside his mouth, filling his throat.

He tries desperately to keep his eyes open, but as the tentacles skewer him even further, his vision goes fuzzy, a dizzying high overtaking him as they begin to thrust, filling both ends with their addictive secretions. His eyelids flutter in his attempts to keep watch on Seonghwa, who is still (miraculously) in a similar debauched state, mouth open around a black tentacle, eyes struggling to stay open.

A small cluster of San’s tentacles slither across Seonghwa’s torso, one of them wrapping around his cock while the others branch off around his thighs. The one coiled around his cock splits open at the tip, revealing miniature versions of itself that plunge into Seonghwa’s slit, eliciting a sharp, shrill moan from the ancient. San smiles inwardly as he watches the shadows of the tiny tendrils appear along the veins of Seonghwa’s cock, rendering it painfully hard, strangled by strings of black.

The cacophanos moans of Seonghwa’s underlings below reverberate off the space’s undulating walls. Seonghwa can’t help the choked moans that fall from his occupied mouth; there are _tiny fucking tentacles in his cock._ Threatening to rip his cum straight from the source, or to rip his cock off entirely. They’re squeezing him from the inside out, thrusting into a hole that’s not made to be thrusted into.

The walls around his space quiver. He has never seen them do that before.

_“I… commend your powers, newblood.”_

Even in San’s head, Seonghwa sounds absolutely _wrecked_ , his voice hoarse from the abuse on his throat. San isn’t any better, but he opts for silence instead as Seonghwa’s tentacles continue to wreak havoc on both ends of him.

Strangely enough, San is able to open his eyes at one point, when he notices a lull in the tentacles’ movements. He’s shocked to see Seonghwa, o powerful ancient, practically bent in half at the spine, head upside down, limbs dangling helplessly in his underlings’ clutch. San grins sadistically at the sight of his tentacle bulging from Seonghwa’s throat while another relentlessly squeezes his cock. Several others roam Seonghwa’s body, painting his skin in a gray translucent slime. Two have suctioned themselves to his nipples, spread out over them like flowers.

It’s _marvelous._

San manages the tiniest of smirks, curling his tongue around the tentacle in his mouth as a sort of _challenge._ Seonghwa gurgles around the obstruction in his throat but manages to receive the message.

San feels a tentacle grazing the head of his cock, and when he glances down, he notices this one has a very… peculiar head.

A bulbous one, but the bulb runs long, matching the length of his cock. The head of it hangs above San’s cock, swinging gently, teasingly.

Whatever it’s about to do, San doesn’t have a good feeling.

_“I want to hear you scream.”_

As the tentacle in his mouth slips out, the one above his cock fissures into four before engulfing San’s entire length in a vacuum of sorts, wet, hot, a continuous tug as it sucks. Though San can’t see what’s happening beneath it, he can feel a million tiny… _things_ attaching themselves to the head of his cock and vibrating at a pace his head can’t keep up with. Just as Seonghwa said, his mouth falls open in a pained, pleasured scream as whatever lies beneath the tentacle services his cock in ways he didn’t even know _existed._

“S-Seonghwa, what is this?” he shouts into the void.

_“Even I don’t know, newblood. I control my underlings to a point. Just as yours are doing this to me, mine are doing this to you.”_

The ability to wield underlings is new territory for San. For as long as he’s had them (which hasn’t been that long), he thought he had complete control over them. But when he’s like this, his body at the mercy of another forest of tentacles, how _could_ he control them? It all makes sense to him now. How his underlings have latched onto Seonghwa like this without him ordering them to. How they’ve been able to keep Seonghwa up like this despite his voice and mind being made useless mush by Seonghwa’s tentacles.

Though bound to him, they have instincts of their own.

“I, too, want to hear you scream,” San growls.

It takes everything in him to keep his voice from breaking.

The tentacles in Seonghwa’s cock stir suddenly, the black branches rippling, bulging, as they erupt from their place.

San watches in awe as Seonghwa’s eyes bug out of his head, black sludge gushing from the sides of his mouth as the tentacle is ripped from it. The viscous fluid bubbles out of his mouth, dripping into shadowy globs as the space consumes it. A garbled moan follows as the same happens with his cock, the same black fluid bursting from the head of his cock, speckled with white and red.

“Oh, _gods_ ,” Seonghwa groans into the abyss, his violet eyes fading to brown as they roll back in his head. His thighs visibly clench as diaphanous white spurts from his cock, cumming in thick ropes as he arches in the firm grasp of San’s tentacles.

“Seonghwa…”

And it doesn’t stop.

Seonghwa _writhes_ as more of his cum shoots up from his cock, landing on his stomach, all the way up to his hairline. Some manages to reach _behind_ him, only to be caught by the walls and washed away into the dark.

As Seonghwa’s orgasm tears through his body, the tentacle encasing San’s cock twists, its suction increasing as the _things_ around the tip speed up.

“Oh, f— _agh_!”

San’s jaw unhinges, mouth dropping into a scream as the tentacle inside his hole swells. The stretch is near _unbearable_ , and when the tentacle around his cock finally releases him, his body fills with a heavy warmth that almost seems to weigh him down despite the tentacles holding him up. Cum bursts from the head of his cock, thighs twitching as he’s filled to the absolute brim, until he can feel it leaking from his hole and there’s a bloating in San’s stomach, a small bump filled with _whatever_ the tentacle plugged him with.

His chest heaves with unneeded breaths as he watches the lump _move_ , the tentacle still buried inside him.

“Take it out!” he exclaims. “Want it out of me, get it out! Get it _out_!”

His tentacles squeeze Seonghwa’s exhausted body. “It’s… your punishment…” he provides weakly. “You did this to me… so they avenge me.”

“Well tell them to take it _out_!”

Seonghwa chuckles. “Newblood… I underestimated your power, but you will not get the best of me.”

“Gods, _fuck you_ , Seonghwa!” He, just like Seonghwa, writhes violently in the tentacles’ grasp, which only churns the liquid sloshing around inside him. It knocks against his walls, against all his organs, hammering on his insides. “Get them to take it out, _now_!”

And then, something spectacular unfolds before San, something he has never seen before, nor something he thought he’d ever see.

All of his tentacles release Seonghwa at once, dropping him to the sea of hands below, and retreat back to their master, pounding and thrashing against Seonghwa’s tentacles in a battle of slimy appendages, until the purple tendrils ultimately withdraw, slipping back into the crack in the space. San’s tentacles cradle their master from below as slick pours from his hole, falling into nothingness and the greedy fingers of Seonghwa’s shadow hands.

“Hey.”

San swallows thickly, his body like jelly in the embrace of his tentacles. His eyes open to see Seonghwa being carried by his hands, mere inches away.

“Don’t… don’t touch me. Don’t come any closer,” San warns, his underlings attentively curled in Seonghwa’s direction.

“I wasn’t going to,” Seonghwa says calmly. “I want to apologize for that.”

San blinks. “I’m sorry, you’re what?”

“Apologizing,” Seonghwa repeats. “Underlings aren’t slaves, San. They have minds of their own. Mine saw what you did to me and wanted to avenge me. That, I couldn’t control. However…” The ancient eyes San’s black tendrils consideringly. “Your powers astounded me, newblood. That, I am willing to admit. It’s rare for newbloods to be able to wield underlings. And yours… are exceptionally talented.”

San looks at his underlings, a strange sense of pride welling up in him.

Seonghwa smirks. “I want to apologize for my rash behavior,” he says. Oddly enough, San can’t sense any insincerity in his voice. “Perhaps I was quick to judge you.”

San’s lip curls in distaste.

“Here.” Seonghwa sighs as the space shifts, revealing what looks to be a bedroom instead of all-encompassing violet walls. The hands dissolve away and their bodies land on a solid ground, a downy carpet colored the hues of Seonghwa’s eyes. “This is my space. Where I truly reside.”

“It looks… human.” San glances around at the room. There is a bed and a nightstand with a lamp on it, a dresser, and a desk. On the desk is an open book with blank pages.

“Sometimes it is nice to feel human,” Seonghwa says. “I would stand, but my body is weary.”

San scoffs. “Tell me about it.”

“Once I am able to stand, however, please allow me to tend to you.”

“I’m sorry?” San gawks at him in disbelief.

“Perhaps I was a little rough on you. And you were certainly rough on me, though perhaps I deserved it.” Seonghwa lets out a low chuckle, a soft smile playing on his face. “I am not cruel, San. Especially not to my own kind. We, even as demons, deserve to be taken care of, no?”

San’s eyes narrow at him. “How am I supposed to trust you?”

“You don’t,” Seonghwa says cryptically. “You don’t trust anybody. But allow yourself to fall into my care, at least for a little while. I will get us both cleaned up and ready for our next endeavors.”

Though San remains dubious and wary of Seonghwa’s sudden hospitality, he figures it couldn’t get much worse than having a tentacle shoved up his ass, cumming what feels like an infinite amount of slime, and _staying_ like that.

So he does as Seonghwa says—he allows himself to fall into Seonghwa’s care, which consists of lying on the floor, recollecting his power to stand. Seonghwa helps him up, and together, they stagger into another room, a bathroom painted a burning crimson. A grandiose bathtub sits in the center, already filled with steaming water that Seonghwa helps San into.

San stares him down from the opposite end. Seonghwa stares back.

Brown on brown.

“May I suggest… a truce, San. One that doesn’t involve a compromise or a contract.”

“What do you mean?”

“I’m saying… we end this petty rivalry of ours,” Seonghwa says with a sigh. “I believe you have learned your lesson, am I right?” San nods. “Perhaps I blew it out of hand by continuing to punish you for your foolish and immature invasion of my space. But I am willing to set everything aside and come to a peaceful settlement.”

San smirks, blinking lazily as he leans forward in the tub, onto his hands and knees, salaciously crawling towards his superior.

“San?” Seonghwa glances down at the newblood, amused.

San brings his head up, leveling his gaze with Seonghwa, fangs bared. He pokes his tongue with one of them and presses his lips to Seonghwa’s, pushing his tongue inside, his blood spreading between their mouths.

When San pulls away, Seonghwa is looking at him with deep violet eyes.

“San?” he says again.

“Seonghwa.”

“What was that?”

San smiles, poking his tongue out, wound-free.

“A truce.”

**Author's Note:**

> i was real lazy with this lol i'm sorry but i didn't want halloween to pass without me posting anything, so here we are :)
> 
> [twitter](https://twitter.com/galaxysangs)


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